gdipluslib.cs

使用TWAIN读取扫描仪的图像。In Windows imaging applications, the most used API for scanning is TWAIN www.twain.o

using System;
using System.IO;
using System.Collections;
using System.Runtime.InteropServices;
using System.Drawing;
using System.Drawing.Imaging;
using System.Windows.Forms;

namespace GdiPlusLib
{


public class Gdip
	{
	private static ImageCodecInfo[] codecs = ImageCodecInfo.GetImageEncoders();

	private static bool GetCodecClsid( string filename, out Guid clsid )
		{
		clsid = Guid.Empty;
		string ext = Path.GetExtension( filename );
		if( ext == null )
			return false;
		ext = "*" + ext.ToUpper();
		foreach( ImageCodecInfo codec in codecs )
			{
			if( codec.FilenameExtension.IndexOf( ext ) >= 0 )
				{
				clsid = codec.Clsid;
				return true;
				}
			}
		return false;
		}


	public static bool SaveDIBAs( string picname, IntPtr bminfo, IntPtr pixdat )
		{
		SaveFileDialog sd = new SaveFileDialog();

		sd.FileName = picname;
		sd.Title = "Save bitmap as...";
		sd.Filter = "Bitmap file (*.bmp)|*.bmp|TIFF file (*.tif)|*.tif|JPEG file (*.jpg)|*.jpg|PNG file (*.png)|*.png|GIF file (*.gif)|*.gif|All files (*.*)|*.*";
		sd.FilterIndex = 1;
		if( sd.ShowDialog() != DialogResult.OK )
			return false;

		Guid clsid;
		if( ! GetCodecClsid( sd.FileName, out clsid ) )
			{
			MessageBox.Show( "Unknown picture format for extension " + Path.GetExtension( sd.FileName ),
							"Image Codec", MessageBoxButtons.OK, MessageBoxIcon.Information );
			return false;
			}
		
		IntPtr img = IntPtr.Zero;
		int st = GdipCreateBitmapFromGdiDib( bminfo, pixdat, ref img );
		if( (st != 0) || (img == IntPtr.Zero) )
			return false;

		st = GdipSaveImageToFile( img, sd.FileName, ref clsid, IntPtr.Zero );
		GdipDisposeImage( img );
		return st == 0;
		}




		[DllImport("gdiplus.dll", ExactSpelling=true)]
	internal static extern int GdipCreateBitmapFromGdiDib( IntPtr bminfo, IntPtr pixdat, ref IntPtr image );

		[DllImport("gdiplus.dll", ExactSpelling=true, CharSet=CharSet.Unicode)]
	internal static extern int GdipSaveImageToFile( IntPtr image, string filename, [In] ref Guid clsid, IntPtr encparams );

		[DllImport("gdiplus.dll", ExactSpelling=true)]
	internal static extern int GdipDisposeImage( IntPtr image );

	}
	
} // namespace GdiPlusLib